This disclosure relates generally to methods and apparatus for guiding a top drive during operation. More specifically, this disclosure relates to a top drive guide system that utilizes an automatic or remotely actuated locking system to secure connections between consecutive sections of guide rail used to form the guide system.
Many drilling rigs utilize top drive units that connect to the uppermost end of the drill string to support the drill sting, provide the torque required to rotate the drill string, and provide a fluid conduit for the circulation of drilling fluids into the drill string. In order to provide this functionality, typical top drives include a drilling motor, pipe handling equipment, and pressure control devices integrated into a single unit. The top drive also includes a dolly, or carriage, that is mounted to a vertical rail, or guide system, that allows the top drive to move freely in a vertical direction but prevents rotation of the top drive as it is applying torque to the drill string and ensures that the top drive remains aligned with the wellbore.
Although some derricks have top drive guide systems permanently installed, many rigs utilize portable top drives that are installed and removed as needed. Installing a top drive guide system often includes assembling a plurality of short guide rail sections together to form a guide rail having the required height. Assembling these guide rail sections often includes hoisting individual guide rail sections into the derrick and utilizing personnel working at elevated positions to secure the connection between adjacent sections. This process can be time consuming and has to be repeated in the reverse to remove the guide system from the drilling rig.
Thus, there is a continuing need in the art for methods and apparatus for assembling and securing top drive guide systems that overcome these and other limitations of the prior art.